MySQL

In the actual project of creating a MySQL scheduled task, you only want to save the records of the last seven days in the MySQL database. It is troublesome and inefficient to delete the records by using SQL commands, event sched provided by Mysql

MYSQL partition field must be included in the primary key field MYSQL partition field. It must be included in the primary key field to partition the table. If the partition field is not included in the primary key field, for example, if the primary

MySql numeric functions abs (N) returns the absolute value of N www.2cto.com mysql> select ABS (2);-> 2 mysql> select ABS (-32);-> 32 sign (N) returns the parameter symbol (-1, 0, or 1) mysql> select SIGN (-32);->-1 mysql> select SIGN (0 ); -> 0

In MySQL, the string space in the query condition is assumed that there is a table in the current mysql database: sysuser has a field: The sysUseName field contains a record: here are the two SQL statements: www.2cto.com SELECT * from sysuser s

Mysql in sorts results by query id. mysql in sorts the returned results by query. If you want to sort the results by query ID,Order by field is used. Here are several examples to illustrate the sorting of mysql in queries: www.2cto.com SQL: select *

Mysql's dump database command recently used the mysql dump database table to record the usage of this command: www.2cto.com mysqldump backup: mysqldump-u username-p password-h host database a-w "SQL condition" -- lock-all-tables> path case:

MySQL auto-increment column inserts 0 values. when migrating a database from MSSQL to MySQL, You need to insert 0 values in the auto-increment column of MySQL based on the requirements of the business logic. This is done in MSSQL: www.2cto.com

Record the helpless power failure caused by a failure to start mysql after a power failure. Mysql cannot be started. 1. view error 130313 15:31:13 [Note] Plugin 'federated 'is disabled. 130313 15:31:13 InnoDB: Initializing buffer pool, size = 107.0

Error Nr is reported at the last step of mysql installation. 1045 solve the problem that the first time mysql database was installed on my computer, it always cracked the crude Nr. 1045 1. go to control panel-> Administrative Tools-> services, open

MySql quick INSERT and batch update INSERT: MySql provides the function of inserting multiple data records at a time: [SQL] insert into tbl_name (a, B, c) VALUES (1, 2, 3 ), (, 6), (, 9), (, 12 )...; in the program, you can add the list of Values

Find the original MySQL deadlock ID. If a deadlock occurs, how can this problem be solved? Find the original lock ID and KILL the thread that has been held all the time. But how can we find the thread ID that causes the deadlock among many threads?

CentOS6.4 install MySQL record choose Linux-Generic instead of Oracle & Ren Hat Linux 6 download the corresponding server and client package, in this I choose 64-bit MySQL-client-5.5.31-2.linux2.6.x86_64.rpmMySQL-server-5.5.31-2.linux2.6.x86_64.rpm

The Optimizer (Optimization Component) of MySql, the Analyze Table MySQL Command, needs to collect related information when optimizing SQL statements, this includes the cardinality of the table (which can be translated as "hash degree "), it

Mysql modification code Linux/Mac/Unix/general modification mysql encoding requires the myslq configuration file, which is in/etc/my. cnf, mac users do not have this file by default. You can find any my-*** In the mysql installation

The mysql client prompts "Cannot proceed because system... "problem: the client prompts "Cannot proceed because system tables used by Event sched1_were found damaged at server start". This is because the current MySQL server version is not

From the perspective of MySQL cold backup, MySQL cold backup is also called offline backup, which is the simplest: ● simple backup: you only need to copy the relevant files. ● simple recovery: simply placing the copied file in the same directory is

Configuration and management of MYSQL in ubuntu I. Installation of MySQL 1. online installation: Command: sudo apt-get install mysql-server during installation, the system will prompt you to set a password for the "root" user and enter your own

$ _ SERVER array element description $ _ SERVER ['php _ SELF '] # File Name of the script being executed, which is related to document root. $ _ SERVER ['argv'] # parameters passed to the script. $ _ SERVER ['argc '] # contains the number of command

I think many of my friends have encountered the problem that the mysql server suddenly stops or starts automatically. Let's analyze the cause and solution to the problem; Cause 1: the automatic backup function of Mysql may cause the database to shut

Mysql tutorial SQL LENGTH, RIGHT, CHAR_LENGTH Character Processing Function LENGTH (str)　 OCTET_LENGTH (str)　 CHAR_LENGTH (str)　 CHARACTER_LENGTH (str)Returns the length of the str string. Mysql> select LENGTH ('text ');-> 4Mysql> select